• The Journal of Information Systems
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• v.28 no.4
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• pp.293-311
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• 2019

Purpose This paper is to make a meta-analysis of the relationship between the social media use and learning performance as well as its potential moderating variables to clarify the differences in research conclusions in existing literatures, and refine the situational and method factors that affect the relationship between them. Methodology Meta-analysis used in this study can combine the quantitative data from different empirical studies, focus on the same research problem, and finally reach a research conclusion. Findings The results show that social media use and learning performance have a moderating positive correlation. The moderating effect test of usage scenarios shows that social media types, usage groups, application platforms and discipline fields have moderating effects on the relationship between social media use and learning performance. The moderating effect test of the research method found that measurement models, data attributes and learning performance indicators also had moderating effects on the relationship between social media use and learning performance.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.5
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• pp.19-28
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• 2015

Korea Digital Copyright Exchange of Korea Copyright Commission runs and manages copyrighted works and copyright license agreement, as well as assigns Integrated Copyright Number(ICN) to copyrighted works, also offers copyrighted works searching service. Keyword-based searching method based on ICN metadata provides results depending on the inclusion of metadata keyword. However, keyword-based searching method has limitations that cannot provide exact results that users need. Therefore, the essential method of offering exact result is needed. In this paper, we propose the semantic-based searching method about copyrighted works to increase the accuracy of searching results by extending ICN matadata to ontology, and implement the ontology of copyrighted works by defining relation and semantics about metadata elements. In order to compare semantic-based searching based on the ontology of copyrighted works with keyword-based searching method, the search results of each method according to 5 scenarios are presented and the accuracy of each method is compared.

• Atmosphere
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• v.26 no.3
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• pp.373-386
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• 2016

The future variability of Wind Energy Density (WED) over the Korean Peninsula under RCP climate change scenario is projected using ensemble analysis. As for the projection of the future WED, changes between the historical period (1981~2005) and the future projection (2021~2050) are examined by analyzing annual and seasonal mean, and Coefficient of Variation (CV) of WED. The annual mean of WED in the future is expected to decrease compared to the past ones in RCP 4.5 and RCP 8.5 respectively. However, the CV is expected to increase in RCP 8.5. WEDs in spring and summer are expected to increase in both scenarios RCP 4.5 and RCP 8.5. In particular, it is predicted that the variation of CV for WED in winter is larger than other seasons. The time series of WED for three major wind farms in Korea exhibit a decrease trend over the future period (2021~2050) in Gochang for autumn, in Daegwanryeong for spring, and in Jeju for autumn. Through analyses of the relationship between changes in wind energy and pressure gradients, the fact that changes in pressure gradients would affect changes in WED is identified. Our results can be used as a background data for devising a plan to develop and operate wind farm over the Korean Peninsula.

• Culinary science and hospitality research
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• v.19 no.2
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• pp.190-202
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• 2013

The arrival and expansion of the Internet has extended consumers' options and has provided consumers' opportunities to offer their own consumption. Through a laboratory experiment, we investigated questions: 1) do consumers trust the accuracy of reviews posted by anonymous reviewers or experts and 2) do readers trust negative and positive reviews equally? The messages were created as a form of 4 scenarios for this study. The statistical analysis was conducted using SPSS Win(v.16.0) for descriptive analysis, and t-test. Our results from a 2(positive reviews vs. negative reviews)*2(consumer vs. expert) experiment design showed that there was a significant difference between consumers' review and experts' one in restaurant visit intention(p<.001) and information credibility(p<.001). Also, between positive review and negative one, significant difference was found in restaurant visit intention(p<.001) and information credibility(p<.01). Other results, limitations and future research directions were also discussed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.7
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• pp.1256-1271
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• 1994

In this paper a GFC protocol based on HMR(High-speed Multimedia Ring) with a dynamic quota allocation is proposed and the performance of proposed protocol is evaluated by simulation. The HMR a medium access protocol proposed for Gbit ATM-LAN, can be applied to the GFC protocol without any modification because it uses only 4 bits for medium access of several topologies such as bus, ring and stared-bus, and priority control for satisfaction of different QoS(Quality of Service) requirements. The quota allocation method of HMR called static quota allocation has a problem of excessive access delay for the traffic with high burstness. In this paper a dynamic quota allocation method which allocates quota to the nodes according to the queue length is proposed and the performance of HMR with dynamic quota allocation is evaluated by seven simulation scenarios of CCITT. The HMR with proposed method shows better shows better access delay characteristics than the HMR with static quota allocation. Also the simulation results show that access delay performance of HMR is better than that of ATMR proposed by Japan and is similar to that of DQDB proposed by Australia.

• Journal of Environmental Science International
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• v.29 no.9
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• pp.871-883
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• 2020

Due to recent heavy rain events, there are increasing demands for adapting infrastructure design, including drainage facilities in urban basins. Therefore, a clear definition of urban rainfall must be provided; however, currently, such a definition is unavailable. In this study, urban rainfall is defined as a rainfall event that has the potential to cause water-related disasters such as floods and landslides in urban areas. Moreover, based on design rainfall, these disasters are defined as those that causes excess design flooding due to certain rainfall events. These heavy rain scenarios require that the design of various urban rainfall facilities consider design rainfall in the target years of their life cycle, for disaster prevention. The average frequency of heavy rain in each region, inland and coastal areas, was analyzed through a frequency analysis of the highest annual rainfall in the past year. The potential change in future rainfall intensity changes the service level of the infrastructure related to hand-to-hand construction; therefore, the target year and design rainfall considering the climate change premium were presented. Finally, the change in dimensional safety according to the RCP8.5 climate change scenario was predicted.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.5
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• pp.1954-1962
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• 2012

Recently the increase in the exchange of goods between Europe and Asia caused by social and economic factors creates good opportunities for railways. At the same time, however, it becomes an enormous challenge for railway transport. There are different rail track gauges (i.e narrow/standard/broad gauge) on the continental transportation between Korea (TKR) and Eurasian (TCR/TSR). The existence of various track gauges is one of obstacles preventing the smooth flow of goods by rail. The transferring process system from one track gauge to another could vary with the types of cargo. Service operation of these systems has a decisive effect on working time and cost of storage and transshipment facilities at border crossings. In relation to the above-mentioned factors, it is important to examine the comparison between different methods of transferring goods in different track gauges. In this study, it was performed to evaluate the effectiveness of continental railway transportation systems through analysis scenarios and to suggest technical factors of them.

• Journal of the Society of Disaster Information
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• v.10 no.1
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• pp.159-169
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• 2014

The development of science and technology to accompany the convenience of civilization but in addition to nuclear, gas, explosion, accident and spill all over the world with the possibility of a chemical or biological terrorism response efforts collectively as a response to the urgent task of a nation. In this study major economies such as the U.S. and Canada analyzed to investigate the CBRN training programs to fit the reality in Korea CBRN training programs were developed. also the development of training programs to CBRN Korean Activity-Action Diagram technique utilized by CBRN scenarios corresponding to each event needs to be taken when the Activity is defined by its detailed definition of corrective actions for the CBRN Activity to define context-sensitive actions in particular to enable the functionality of the structure in case of CBRN emergency initial response was to establish education and training programs.

• Journal of the Institute of Convergence Signal Processing
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• v.9 no.1
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• pp.39-45
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• 2008

This paper considers the multi-objective optimization of a multi-service arrayed waveguide grating-based single-hop WDM network with the two conflicting objectives of maximizing throughput while minimizing delay. This paper presents a genetic algorithm based methodology for finding the optimal throughput-delay tradeoff curve, the so-called Pareto-optimal frontier. Genetic algorithm based methodology provides the network architecture parameters and the Medium Access Control protocol parameters that achieve the Pareto-optima in a computationally efficient manner. The numerical results obtained with this methodology provide the Pareto-optimal network planning and operation solution for a wide range of traffic scenarios. The presented methodology is applicable to other networks with a similar throughput-delay tradeoff.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.659-660
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• 2016

This paper presents an improved evaluation method, based on National Competency Standards (NCS), of National Technical Qualification (NTQ) examination in Electronics Fields such as Craftsman Computer, Industrial Engineer Computer Maintenance Control, Engineer Computer System Application, Engineer Computer, Engineer Embedded) to reflect practical vocational abilities and raise values of NTQ certificates. To evaluate each NTQ examination, we carefully chose corresponding NCS competency units for practical performance test, written subjective test, and mixed test through the advisory committee with industry, education, and qualification experts. In addition, we verified useful effects of the NCS-based evaluation method by performing and analyzing the simulated tests. We used both single and mixed problems in practical performance test and new problems about system design and implementation based on various working scenarios in written subjective test.